Was Warren Buffett Wrong to Buy ExxonMobil Over Chevron?Motley FoolBerkshire Hathaway's portfolio consists of 43 companies and is worth $92 billion. In 2013, the company purchased nearly 1% of ExxonMobil (NYSE: XOM ) . This represents about 3.5% of Berkshire's overall holdings and about 50% of its investments in the …